We report high temperature surface acoustic wave (SAW) gas sensors with conducting sensing layers require tuning of the sheet conductivity for optimal response. Conducting metal oxides are attractive sensing materials for their tunable electronic properties and high thermal stability, amongst others. Here, we have investigated the application of indium oxide (IO) and indium tin oxide (ITO) films on langasite (LGS)-based SAW reflective delay line sensor devices for monitoring hydrogen at 350 °C. Specifically, we modeled the effect of the IO and ITO sensing layer thickness on the wave velocity, attenuation, and effective electromechanical coefficient. This was followed by an experimental demonstration of tuning of the ITO film sheet conductivity by controlling the dopant concentration and yielding an improvement in the sensor sensitivity. The current study provides a pathway towards the development of conductivity-based sensing layers for high temperature SAW gas sensors with improved sensitivity.
Devkota, Jagannath, Mao, Elizabeth, Greve, David W., Ohodnicki, Paul R., & Baltrus, John (2021). A surface acoustic wave hydrogen sensor with tin doped indium oxide layers for intermediate temperatures. Sensors and Actuators. B, Chemical, 354(None). https://doi.org/10.1016/j.snb.2021.131229
Devkota, Jagannath, Mao, Elizabeth, Greve, David W., et al., "A surface acoustic wave hydrogen sensor with tin doped indium oxide layers for intermediate temperatures," Sensors and Actuators. B, Chemical 354, no. None (2021), https://doi.org/10.1016/j.snb.2021.131229
@article{osti_1868089,
author = {Devkota, Jagannath and Mao, Elizabeth and Greve, David W. and Ohodnicki, Paul R. and Baltrus, John},
title = {A surface acoustic wave hydrogen sensor with tin doped indium oxide layers for intermediate temperatures},
annote = {We report high temperature surface acoustic wave (SAW) gas sensors with conducting sensing layers require tuning of the sheet conductivity for optimal response. Conducting metal oxides are attractive sensing materials for their tunable electronic properties and high thermal stability, amongst others. Here, we have investigated the application of indium oxide (IO) and indium tin oxide (ITO) films on langasite (LGS)-based SAW reflective delay line sensor devices for monitoring hydrogen at 350 °C. Specifically, we modeled the effect of the IO and ITO sensing layer thickness on the wave velocity, attenuation, and effective electromechanical coefficient. This was followed by an experimental demonstration of tuning of the ITO film sheet conductivity by controlling the dopant concentration and yielding an improvement in the sensor sensitivity. The current study provides a pathway towards the development of conductivity-based sensing layers for high temperature SAW gas sensors with improved sensitivity.},
doi = {10.1016/j.snb.2021.131229},
url = {https://www.osti.gov/biblio/1868089},
journal = {Sensors and Actuators. B, Chemical},
issn = {ISSN 0925-4005},
number = {None},
volume = {354},
place = {United States},
publisher = {Elsevier},
year = {2021},
month = {12}}
2011 Joint Conference of the IEEE International Frequency Control and the European Frequency and Time Forum (FCS) Proceedingshttps://doi.org/10.1109/FCS.2011.5977811